Freshwater scarcity is a global challenge threatening human survival, especially for people living in arid regions. Sorption‐based atmospheric water harvesting (AWH) is an appealing way to solve this problem. However, the state‐of‐the‐art AWH technologies have poor water harvesting performance in arid climates owing to the low water sorption capacity of common sorbents under low humidity conditions. We report a high‐performance composite sorbent for efficient water harvesting from arid air by confining hygroscopic salt in a metal–organic framework matrix (LiCl@MIL‐101(Cr)). The composite sorbent shows 0.77 g g−1 water sorption capacity at 1.2 kPa vapor pressure (30 % relative humidity at 30 °C) by integrating the multi‐step sorption processes of salt chemisorption, deliquescence, and solution absorption. A highly efficient AWH prototype is demonstrated with LiCl@MIL‐101(Cr) that can enable the harvesting of 0.45–0.7 kg water per kilogram of material under laboratory and outdoor ambient conditions powered by natural sunlight without optical concentration and additional energy input.

Efficient thermal energy harvesting using phase‐change materials (PCMs) has great potential for cost‐effective thermal management and energy storage applications. However, the low thermal conductivity of PCMs (KPCM) is a long‐standing bottleneck for high‐power‐density energy harvesting. Although PCM‐based nanocomposites with an enhanced thermal conductivity can address this issue, achieving a higher K (>10 W m−1 K−1) at filler loadings below 50 wt% remains challenging. A strategy for synthesizing highly thermally conductive phase‐change composites (PCCs) by compression‐induced construction of large aligned graphite sheets inside PCCs is demonstrated. The millimeter‐sized graphite sheet consists of lateral van‐der‐Waals‐bonded and oriented graphite nanoplatelets at the micro/nanoscale, which together with a thin PCM layer between the sheets synergistically enhance KPCM in the range of 4.4–35.0 W m−1 K−1 at graphite loadings below 40.0 wt%. The resulting PCCs also demonstrate homogeneity, no leakage, and superior phase change behavior, which can be easily engineered into devices for efficient thermal energy harvesting by coordinating the sheet orientation with the thermal transport direction. This method offers a promising route to high‐power‐density and low‐cost applications of PCMs in large‐scale thermal energy storage, thermal management of electronics, etc.

Fresh water scarcity is a globally significant challenge threatening the development of human society. Sorption-based atmospheric water harvesting offers an appealing way to solve this challenge by extracting clean water...

No abstract

Phase change materials (PCMs) have been widely used for passive thermal management and energy storage due to the high latent heat capacity near phase transition points. However, the low thermal...